Sniffing instrument for detecting low-concentration naturally volatile gas of drugs and use method of sniffing instrument

Abstract

The invention belongs to the technical field of drug detection, and particularly discloses a sniffer for detecting low-concentration natural volatile gas of drugs, which is characterized in that a working cavity is formed in a shell; the sensor reaction chamber and the MOFs adsorption tower are arranged in the working cavity and are communicated with each other, and the MOFs adsorption tower is used for adsorbing, pre-concentrating and desorbing gas of a to-be-detected product and transmitting the gas into the sensor reaction chamber; the input gas path is provided with a first electromagnetic valve and a first gas pump, and the first gas pump is connected with the MOFs adsorption tower through the first electromagnetic valve; the detection gas circuit is provided with a second electromagnetic valve and a second gas pump, one end of the second electromagnetic valve is connected with the MOFs adsorption tower and the first electromagnetic valve, and the other end of the second electromagnetic valve is connected with the sensor reaction chamber through the second gas pump; one end of the output gas circuit is connected with the second gas pump and the sensor reaction chamber through the third solenoid valve, and the other end of the output gas circuit exhausts gas. The drug detection kit can rapidly detect drugs and is convenient to carry. The invention also discloses a use method of the sniffer for detecting the low-concentration natural volatile gas of the drugs.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drug detection, and particularly relates to a sniffer for detecting low-concentration natural volatile gas of drugs and a use method. BACKGROUND

[0002] Drugs seriously endanger human health and social peace, and the prevention and control of drug proliferation is a key content of government work. Customs and public security departments take airports, stations and densely populated areas as key places for drug inspection, however, criminals often hide drugs through packaging, sealing and other means, so that the natural volatile odor concentration of many drugs is extremely low, which greatly increases the difficulty of drug detection.

[0003] At present, existing drug detection technologies have advantages and disadvantages. For example, gas chromatography-mass spectrometry (GC-MS) is a common detection method, which separates the components in the volatile gas of drugs through gas chromatography, and then performs high-sensitivity qualitative and quantitative analysis by mass spectrometry, so the detection accuracy is quite high. However, this technology has obvious disadvantages: the equipment is large in size and not portable, the detection sample needs pre-treatment, the detection efficiency is low, the equipment operation is difficult, and systematic learning of relevant professional knowledge is required.

[0004] Another detection method is to use drug detection dogs. Drug detection dogs can track the odor molecules of natural volatile substances of drugs by virtue of their strong olfactory ability, and can detect PPT-level (trillionth) natural volatile substance odor molecules of drugs, with extremely low detection concentration lower limit. However, biological olfaction is easy to fatigue, and the detection work of drug detection dogs is highly dependent on the cooperation of trainers.

[0005] Therefore, in the process of hiding and transporting drugs, how to realize rapid screening, accurate identification, easy operation, portability and long-time work of the drug detection equipment for low-concentration natural volatile odor of drugs is an urgent problem to be solved in the drug suppression and control work of customs and public security departments. SUMMARY

[0006] The purpose of the present application is to provide a low-concentration sniffer for detecting natural volatile gas of drugs, which can rapidly screen, is easy to operate, does not require pre-treatment, is easy to carry and is not limited by use time.

[0007] The purpose of the present application is achieved by such a technical solution, and specifically provides a low-concentration sniffer for detecting natural volatile gas of drugs, comprising:

[0008] A shell having a working cavity inside;

[0009] A sensor reaction chamber and a MOFs adsorption tower are arranged in the working cavity and are communicated, the MOFs adsorption tower is used for adsorbing, pre-concentrating and desorbing the gas of the to-be-detected product, and the desorbed gas is transmitted into the sensor reaction chamber.

[0010] The input gas path is provided with a first electromagnetic valve, a first air pump and a sniffing head, one end of the first air pump is connected with the sniffing head, and the other end is connected with the MOFs adsorption tower through the first electromagnetic valve;

[0011] The detection gas path is provided with a second electromagnetic valve and a second air pump, one end of the second electromagnetic valve is connected with the MOFs adsorption tower and the first electromagnetic valve respectively, and the other end is connected with the sensor reaction chamber through the second air pump;

[0012] The output gas path is provided with a third electromagnetic valve, one end of the third electromagnetic valve is connected with the second air pump and the sensor reaction chamber respectively, and the other end is connected with the sensor reaction chamber.

[0013] Preferably, the MOFs adsorption tower comprises a plurality of heating sheets, a plurality of condensing sheets, a first shell and a MOFs adsorption tower body, the MOFs adsorption tower body is sealingly arranged in the first shell, and the heating sheets and the condensing sheets are arranged at intervals along the circumference of the first shell.

[0014] Preferably, the MOFs adsorption tower body is coated with MOFs material with a thickness of 20-30 μm.

[0015] Preferably, the MOFs adsorption tower further comprises a heat insulation sheet, and the heat insulation sheet is wrapped outside the heating sheets and the condensing sheets.

[0016] Preferably, the input gas path further comprises a filtering device and a drying tube, and the filtering device and the drying tube are arranged in sequence from the sniffing head to the first air pump.

[0017] Preferably, the sensor reaction chamber comprises a sensor array and a second shell, the sensor array is arranged in the second shell, and the sensor array comprises semiconductor sensors and electrochemical sensors arranged at intervals.

[0018] Preferably, the device further comprises a storage battery, and the storage battery is arranged in the working cavity.

[0019] Preferably, the shell further comprises a hand-held part.

[0020] Due to the adoption of the above technical scheme, the device has the following advantages:

[0021] By arranging the MOFs adsorption tower, the sensor reaction chamber and the gas paths, the MOFs adsorption tower completes the adsorption, pre-concentration and desorption of the natural volatile gas of the to-be-detected product in the closing or conduction of the gas paths, the sensor reaction chamber detects the desorbed gas, and the drug is quickly and accurately detected.

[0022] Another object of the present application is to provide a use method of the sniffing instrument for detecting low-concentration natural volatile gas of drugs, which uses the sniffing instrument for detecting low-concentration natural volatile gas of drugs to adsorb, pre-concentrate and desorb the low-concentration gas volatilized from the to-be-detected product, and detects the drug by the sniffing instrument.

[0023] Another object of the present invention is achieved through such a technical solution, specifically providing a method for using a sniffer for detecting low-concentration natural volatile gas of drugs, comprising the following steps:

[0024] S1. Place the portable sniffer close to the object to be tested.

[0025] S2. Gas Sample Collection: The MOFs adsorption tower cycles through adsorption, pre-concentration, and desorption of the volatile gases of the test sample, and discharges the desorbed gases into the sensor reaction chamber.

[0026] S3. Analyze and compare gas samples: The sensor reaction chamber analyzes the data, and the control system compares the data similarity in the database, makes a judgment on the product to be tested, and the test is completed.

[0027] Preferably, step S2 further includes the following steps:

[0028] S21. Filtering and drying the adsorbed gas;

[0029] S22. Using airflow to clean the MOFs adsorption tower, sensor reaction chamber, and gas lines;

[0030] S23. The MOFs adsorption tower absorbs and sniffs the natural volatile gases of the test product and performs pre-concentration;

[0031] S24. The MOFs adsorption tower is subjected to gradient temperature heating and desorption. Different MOFs materials have different desorption effects on different odor molecules at different temperatures, achieving selective desorption and discharging them into the sensor reaction chamber in sections.

[0032] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0033] The invention provides a method for using a sniffer for detecting low-concentration natural volatile gas of drugs, which can quickly detect drugs with low-concentration natural volatile odors, is easy to carry and operate, and does not require pre-treatment of samples to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0035] Figure 1 This is a schematic structural diagram of a sniffer for detecting low-concentration natural volatile gases of drugs according to the present invention;

[0036] Figure 2 This is a schematic diagram of the gas purge process in the first step of the test process;

[0037] Figure 3This is a schematic diagram of the gas collection process in the second step of the test process;

[0038] Figure 4 This is a schematic diagram of the gas detection process in the third step;

[0039] Figure 5 This is a schematic diagram of the gas line installation;

[0040] Figure 6 Schematic diagram of the structure of the MOFs adsorption tower;

[0041] Figure 7 Schematic diagram of the thermal insulation sheet installed on the MOFs adsorption tower;

[0042] Figure 8 Schematic diagram of the structure of the sensor reaction chamber;

[0043] Figure 9 A schematic diagram of the overall structure of a sniffer for detecting low-concentration natural volatile gases of drugs.

[0044] Reference numerals:

[0045] 1-housing, 11-working chamber, 12-upper housing, 13-lower housing, 14-handle, 15-display screen;

[0046] 2-MOFs adsorption tower, 21-heating plate, 22-condensing plate, 23-first shell, 231-third gas port, 24-MOFs adsorption tower body, 25-thermal insulation plate, 26-first three-way connector;

[0047] 3 - sensor reaction chamber, 31 - sensor array, 311 - semiconductor sensor, 312 - electrochemical sensor, 32 - second housing, 321 - second housing body, 322 - bottom cover, 323 - sealing gasket, 324 - sealing gasket groove, 325 - first air port, 326 - second air port, 327 - temperature sensor; 33 - second three-way connector;

[0048] 4-input air line, 41-solenoid valve, 42-first air pump, 43-sniffing probe, 44-filter device, 45-drying tube;

[0049] 5- detection air circuit, 51- second solenoid valve, 52- second air pump;

[0050] 6- output gas line, 61- third solenoid valve;

[0051] 7-Control system; 8-Battery; 9-Power switch. DETAILED DESCRIPTION

[0052] The embodiments of the technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0053] See also Figure 1 、 Figure 5 and Figure 9 A sniffer for detecting low-concentration natural volatile gas of drugs includes a shell 1, a MOFs adsorption tower 2, a sensor reaction chamber 3, an input gas path 4, a detection gas path 5 and an output gas path 6.

[0054] A working chamber 11 is provided inside the shell 1; the sensor reaction chamber 3 and the MOFs adsorption tower 2 are arranged in the working chamber 11, and the sensor reaction chamber 3 and the MOFs adsorption tower 2 are connected. The MOFs adsorption tower 2 is used to adsorb, pre-concentrate and desorb the gas of the test sample, and transmit the desorbed gas to the sensor reaction chamber 3; the input gas circuit 4 is provided with a first solenoid valve 41, a first air pump 42 and a sniffer probe 43, one end of the first air pump 42 is connected to the sniffer probe 43, and the other end is connected to the MOFs adsorption tower 2 through the first solenoid valve 41; the detection gas circuit 5 is provided with a second solenoid valve 51 and a second air pump 52, one end of the second solenoid valve 51 is respectively connected to the MOFs adsorption tower 2 and the first solenoid valve 41, and the other end is connected to the sensor reaction chamber 3 through the second air pump 52; the output gas circuit 6 is provided with a third solenoid valve 61, one end of which is connected to the second air pump 52 and the sensor reaction chamber 3 respectively through the third solenoid valve 61, and the other end is exhausted. Specifically, the housing 1 is made of plastic and is relatively lightweight. The housing 1 is divided into an upper housing 12 and a lower housing 13. After the components are assembled and tested, the upper housing 12 and the lower housing 13 are ultrasonically heat-welded, and the sealing between the upper housing 12 and the lower housing 13 is good. The dimensions of the housing 1 are 402 mm in length, 138 mm in width, and 198 mm in height. A control system 7 is provided in the working chamber 11. The control system 7 is electrically connected to the first solenoid valve 41, the first air pump 42, the second solenoid valve 51, the second air pump 52, the third solenoid valve 61, the sensor reaction chamber 3, and the MOFs adsorption tower 2. The control system 7 stores test instruction programs and various drug detection parameters and other data. A power switch 9 is provided on the outside of the upper housing 12. The MOFs adsorption tower 2 is provided with a first three-way joint 26, one end of the first three-way joint 26 is connected to the first solenoid valve 41, one end is connected to the second solenoid valve 51, and one end is connected to the MOFs adsorption tower 2; the sensor reaction chamber 3 is provided with a second three-way joint 33, one end of the second three-way joint 33 is connected to the second air pump 52, one end is connected to the third solenoid valve 61, and the other end is connected to the sensor reaction chamber 3.

[0055] The present invention is a sniffer for detecting low concentration natural volatile gas of drugs. When in use, first place the sniffer probe 43 toward the object to be tested, then press the power switch 9. The first step of the test process is: Figure 2, the first solenoid valve 41, the first air pump 42, the second solenoid valve 51, the second air pump 52, and the third solenoid valve 61 are in working state, the gas enters the MOFs adsorption tower 2 through the input gas line 4, and then passes through the sensor reaction chamber 3 and is discharged through the output gas line 6. At the same time, part of the gas enters the detection gas line 5 through the input gas line 4, flows through the second solenoid valve 51 and is discharged through the output gas line 6. The purpose of the first step of the test process is to clean the MOFs adsorption tower 2, the sensor reaction chamber 3 and the gas channel, remove the gas remaining in each gas line and component, and improve the purity of the gas to be tested. The second step of the test process: Figure 3 , close the second solenoid valve 51 and the second air pump 52, and the air flows in from the input air path 4, passes through the first solenoid valve 41, and enters the MOFs adsorption tower 2 to adsorb the natural volatile gas of the test product. After adsorption, it passes through the sensor reaction chamber 3 and is discharged from the output air path 6. This cycle is repeated, and the MOFs adsorption tower 2 continuously accumulates and pre-concentrates the low-concentration natural volatile gas of the test product to complete the gas collection. The third step of the test process: Figure 4 The first solenoid valve 41, the third solenoid valve 61, and the first air pump 42 are closed, while the second solenoid valve 51 and the second air pump 52 are opened. Simultaneously, pulse heating is applied to the MOFs adsorption tower 2, desorbing the gas adsorbed there. The desorbed gas is extracted by the detection gas path 5 to purge the MOFs adsorption tower 2, and then is extracted by the second air pump 52 after passing through the sensor reaction chamber 3. This cycle is repeated to increase the concentration of the natural volatile gas of the test substance in the gas path. Finally, considering the different desorption effects of natural volatiles of different drugs at different temperatures, the sensor reaction chamber 3 generates data on the changes in the gas reaction. The system then begins analyzing the data and compares it with the data in the database for similarity, thereby determining whether the test substance is a drug and confirming its type. The MOFs adsorption tower 2 is used to adsorb and pre-concentrate the naturally volatile gases of the test sample, and then heating is used to desorb the gases. The sensor reaction chamber 3 detects the gases and feeds the information back to the control system 7, which can quickly complete the sample collection and detection work. The desorption adopts the variable temperature desorption method, which effectively reduces cross interference. The detection information is compared with big data and the detection accuracy is high.

[0056] Furthermore, the MOFs adsorption tower 2 includes a plurality of heating fins 21, a plurality of condensing fins 22, a first shell 23 and a MOFs adsorption tower body 24. The MOFs adsorption tower body 24 is sealed in the first shell 23, and the heating fins 21 and the condensing fins 22 are spaced apart along the circumference of the first shell 23. Specifically, the first shell 23 is made of 304 stainless steel, which has good thermal conductivity. The heating fins 21 and the condensing fins 22 are spaced apart along the circumference of the first shell 23 to uniformly dissipate heat or heat the MOFs adsorption tower body 24. Preferably, two heating fins 21 and two condensing fins 22 are respectively provided. The two heating fins 21 are respectively provided on the upper surface and the lower surface of the first shell 23, and the two condensing fins 22 are respectively provided on the left surface and the right surface of the first shell 23. A third air port 231 is respectively provided at both ends of the first shell 23, and the third air port 231 is symmetrically provided on the front surface and the rear surface of the first shell 23. The heating plate 21 uses a microfluidic channel integrated heater to quickly heat the adsorption tower body 24. Since the desorption temperatures of volatile gases of various drugs are different, such as 145°C for desorption of methamphetamine and 195°C for desorption of fentanyl, etc., combined with the different desorption effects of different natural volatile substances of different drugs at different temperatures, variable temperature desorption can be performed, thereby reducing cross-contamination and improving identification accuracy. The MOFs adsorption tower body 24 uses a multi-channel honeycomb adsorption column, and its channels are coated with specific MOFs materials. MOFs (Metal-Organic Frameworks) are a type of porous crystalline material formed by self-assembly of metal ions or clusters and organic ligands through coordination bonds. It has ultra-high specific surface area and porosity. The specific surface area of ​​MOFs can reach 1000-7000m 2 / g (e.g., the specific surface area of ​​MOF-210 is as high as 6240 m 2 / g), far exceeding traditional porous materials (such as zeolite, activated carbon); the porosity is as high as 90%, and the pore structure is adjustable, which can provide a large number of active sites for applications such as gas adsorption and separation. By selecting different metal ions or clusters (such as Zn 2+ 、Cu 2+ 、Zr 4+ etc.) and organic ligands (such as carboxylic acids and imidazoles) can precisely control the pore size; organic ligands can introduce functional groups such as -NH2, -OH, and -COOH to give the material specific chemical properties. For example: A. UiO-66, the functional group -COOH is introduced, and the carboxyl group enhances the ability to bind to the hydrogen bond of methamphetamine-ice; B. MIL-101 (Cr / Al), the functional group -NH2 is introduced, forming hydrogen bonds with the -OH of THC and the ester group of heroin; the functional group -SO3H is introduced, and after protonation, it electrostatically attracts the amino group of methamphetamine / MDMA. C. ZIF-8 derivatives, the functional group -SH is introduced, forming a sulfur-oxygen interaction with the methylenedioxy group of MDMA; the introduction of Ag +Coordinated with the ester group of heroin. Using the MOFs adsorption tower body 24, with the assistance of the second air pump 52, the first air pump 42, and the heater 21, the air flow rate is controlled at 1 L / min. In approximately three minutes, the concentration of the natural volatiles of the analyte can be increased by 1000 times. Then, through heating and dry air purging, different drugs are selectively desorbed into the sensor reaction chamber 3 at different temperatures, shortening the detection process.

[0057] Furthermore, the thickness of the MOFs material coated on the MOFs adsorption tower body 24 is 20-30 μm. If the thickness is greater than 30 μm, the desorption efficiency will be affected, and if the thickness is less than 20 μm, the structural stability of the MOFs material will be poor.

[0058] Furthermore, the MOFs adsorption tower 2 also includes a heat shield 25, which is coated on the outside of the heating plate 21 and the condensing plate 22. Specifically, the heat shield 25 is made of ceramic to prevent the heating plate 21 from radiating heat to surrounding parts during operation, causing local overheating and affecting the normal operation of the parts.

[0059] Furthermore, the input gas path 4 also includes a filter device 44 and a drying tube 45, which are sequentially arranged from the sniffer probe 43 to the first air pump 41. Specifically, the filter device 44 and drying tube 45 are arranged outside the housing 1, facilitating maintenance and replacement of the filter device 44 and drying tube 45, eliminating the need to disassemble the housing 1 to replace consumables. The filter device 44 utilizes existing technology, such as a combination of multiple non-partitioned filters, and the drying tube 45 is arranged at the rear end of the filter device 44. Pre-processing of the gas to dry and remove particulate interference improves detection accuracy.

[0060] Furthermore, the sensor reaction chamber 3 comprises a sensor array 31 and a second housing 32. The sensor array 31 is disposed within the second housing 32 and includes spaced semiconductor sensors 311 and electrochemical sensors 312. Specifically, the second housing 32 is made of stainless steel and includes a second housing body 321, a bottom cover 322, and a sealing gasket 323. A sealing gasket groove 324 is circumferentially defined along the bottom end surface of the second housing body 321. The sealing gasket 323 is mounted within the groove 324, with the height of the sealing gasket 323 slightly greater than the depth of the groove 324. The bottom cover 322 is screwed to the second housing body 321, forming a sealed chamber. The sensor reaction chamber 3 is provided with a first gas port 325, which communicates with the MOFs adsorption tower 2. The first gas port 325 is located on the upper end surface of the second housing 32. The sensor reaction chamber 3 is also provided with a second gas port 326, which communicates with the output gas path 6. The second gas port 326 is located on the side end surface of the second housing 32. The first gas inlet 325 and the second gas inlet 326 are staggered, and the first gas inlet 325 connected to the MOFs adsorption tower 2 is set on the upper end surface, which prolongs the residence time of the gas in the sensor reaction chamber 3 and increases the number of target gases reacting with the sensor array 31, thereby improving the detection accuracy of the sensor array 31. The sensor array 31 is composed of a combination of multiple semiconductor sensors 311 and multiple electrochemical sensors 312, with a response time of ≤60S, and can measure a variety of drugs.

[0061] The semiconductor sensors 311 include but are not limited to: A. TGS2602 (Figaro), broad-spectrum VOC detection, sensitive to amines and benzene series (sensitive to methylenedioxy structure); B. TGS822 (Figaro): strong response to solvents such as acetone, ethanol, and benzene (can detect residual solvents in drug production); C. MQ-135 (Hanwei): sensitive to ammonia, sulfides, and benzene series (suitable for amine detection). D. SGX Sensortech MiCS-5526, ethanol, benzene, acetone (but has cross-response to oxygen-containing benzene ring compounds), etc. Electrochemical sensors include but are not limited to: ME3-NH3 (Winsen): dedicated to ammonia detection (methamphetamine free base volatilizes and contains ammonia smell);

[0062] AlphasenseCO-A4: Can detect volatile amines (electrode material optimization is required).

[0063] Screen-Printed Electrodes (SPE): such as DRP-110 (carbon electrode) or DRP-220 (gold electrode), which can be customized with MIP templates or nanomaterial modifications that match the molecular structure of heroin.

[0064] Furthermore, the sensor reaction chamber 3 includes a temperature sensor 327, which is disposed within the sensor reaction chamber 3. Specifically, the temperature sensor 327 is disposed below the first gas port 325 and is electrically connected to the control system 7. The temperature sensor 327 is used to monitor the gas temperature within the sensor reaction chamber 3 and transmit the temperature information to the control system 7.

[0065] Furthermore, the device further comprises a battery 8, which is disposed in the working chamber 11. The battery 8 provides a driving source for the sniffer, thereby improving the outdoor usage scenario of the sniffer.

[0066] Furthermore, the housing 1 is also provided with a handle 14. Specifically, it is provided on the surface of the upper housing. In order to conveniently turn on or off the power switch 9, the power switch 9 is provided on the surface of the handle 14. With this structure, it is convenient to carry the sniffer and press the power switch 9.

[0067] Furthermore, a display screen 15 is included, which is arranged at the front end of the housing 1. Specifically, the display screen 15 is electrically connected to the control system 7, and the detection results are displayed on the display screen 15.

[0068] The present invention also provides a method for using a sniffer for detecting low-concentration natural volatile gas of drugs, comprising the following steps:

[0069] S1. Place the portable sniffer close to the object to be tested.

[0070] S2. Gas Sample Collection: The MOFs adsorption tower cycles through adsorption, pre-concentration, and desorption of the volatile gases of the test sample, and discharges the desorbed gases into the sensor reaction chamber.

[0071] S3. Analyze and compare gas samples: The sensor reaction chamber analyzes the data, and the control system compares the data similarity in the database, makes a judgment on the product to be tested, and the test is completed.

[0072] Specifically, before testing, first check the power and display status of the sniffer to ensure the self-test of the sniffer. Move the sniffer toward the product to be tested, and then press the power switch. The MOFs adsorption tower 2 is provided with a multi-channel honeycomb adsorption column, and a specific MOFs material is coated in its channel. The MOFs material absorbs and pre-concentrates the natural volatile gas of the product to be tested; the MOFs adsorption tower 2 is provided with a heating plate 21 to heat the pre-concentrated gas in the MOFs adsorption tower 2. Different temperatures have different desorption effects on the natural volatiles of different drugs. Variable temperature desorption can be performed, and the desorbed gas is sent to the sensor reaction chamber 3. The sensor reaction chamber 3 uses the gas analysis information to compare the data similarity in the database to determine the drug category of the product to be tested. After the test is completed, move away from the product to be tested, and start the power switch 9 again to clear the residual gas in the sniffer.

[0073] Furthermore, step S2 also includes the following steps:

[0074] S21. Filtering and drying the adsorbed gas;

[0075] S22. Using airflow to clean the MOFs adsorption tower, sensor reaction chamber, and gas lines;

[0076] S23. The MOFs adsorption tower absorbs and sniffs the natural volatile gases of the test product and performs pre-concentration;

[0077] S24. The MOFs adsorption tower is subjected to gradient temperature heating and desorption. Different MOFs materials have different desorption effects on different odor molecules at different temperatures, achieving selective desorption and discharging them into the sensor reaction chamber in sections.

[0078] Specifically, the sniffer is equipped with a filter device 44 and a drying tube 45. The volatile gas of the test object is first removed from interfering impurities such as dust and moisture to improve the purity of the gas and the fluidity of the sniffer. The sniffer includes an input gas circuit 4 provided with a first solenoid valve 41 and a first air pump 42, a detection gas circuit provided with a second solenoid valve 51 and a second air pump 52, and an output gas circuit 6 provided with a third solenoid valve 61. In step S22, each air pump and solenoid valve is in a working state, and the gas enters the MOFs adsorption tower 2 through the input gas circuit 4, passes through the sensor reaction chamber 3, and is discharged through the output gas circuit 6. At the same time, part of the gas enters the detection gas circuit 5 through the input gas circuit 4, and is then discharged through the output gas circuit 6. This process serves to clean the MOFs adsorption tower 2, the sensor reaction chamber 3, and each gas flow channel. In step S23, the second solenoid valve 51 and the second air pump 52 are closed, and the air flow flows in from the input air path 4, passes through the first solenoid valve 41, enters the MOFs adsorption tower 2 to adsorb the natural volatile gas of the test product, and is discharged from the output air path 6 through the sensor reaction chamber 3 after adsorption. This cycle is repeated, and the MOFs adsorption tower 2 continuously accumulates and pre-concentrates the natural volatile gas of the test product. In step 24, the first solenoid valve 41, the second solenoid valve 51 and the first air pump 42 are closed, and the second solenoid valve 51 and the second air pump 52 are opened. At the same time, the MOFs adsorption tower is pulse-heated, and the gas is extracted from the detection air path 5 to purge the MOFs adsorption tower, thereby desorbing the adsorbed gas, and then extracted by the second air pump 52 after passing through the sensor reaction chamber 3. This cycle is repeated to increase the concentration of the natural volatile gas of the test product in the air path. Because the desorption temperatures of volatile gases of various drugs are different, the following table shows the desorption temperatures of typical drugs on the MOFs adsorption tower:

[0079] 1. Desorption temperature range of typical drugs on MOFs

[0080]

[0081] The temperature gradient can be divided into four sections: 80℃-120℃, 120℃-160℃, 160℃-200℃, and 200℃-250℃. When in use, the temperature is heated by the heating plate 21 from low temperature to high temperature. Different temperatures have different desorption effects on natural volatile substances of different drugs. Gradient temperature desorption is used, and the sensor reaction chamber 3 detects the gas and feeds back the information to the control system 7. The control system 7 compares the detection information with big data, and the detection accuracy is high.

[0082] The present invention provides a sniffer for detecting low-concentration natural volatile gases of drugs and a method for using the same. The MOFs adsorption tower 2 is provided with a multi-channel honeycomb adsorption column, and a specific MOFs material is coated in its channels. The MOFs adsorption tower 2 is also provided with a heating plate 21 to complete the collection, pre-concentration and desorption of the natural volatiles of the test product, and the desorption temperatures of different drugs are different. The sensor reaction chamber 3 is provided with corresponding semiconductor sensors 311 and electrochemical sensors 312, so that the sniffer can detect low-concentration volatile gases of the test product quickly, efficiently and with high precision. A filter device 44 and a drying tube 45 are provided for pre-processing of the gas to dry and remove particulate interferences, thereby increasing the accuracy of the detection. A battery 8, a portable part 14 and a display screen 15 are provided to improve the application scenarios of the sniffer. The sniffer is small in size and easy to carry.

[0083] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sniffer for detecting low-concentration natural volatile gases of drugs, characterized in that: include: A housing (1) is provided with a working chamber (11) therein; The sensor reaction chamber (3) and the MOFs adsorption tower (2) are arranged in the working chamber (11) and are in communication with each other. The MOFs adsorption tower (2) is used for adsorbing, pre-concentrating and desorbing the gas of the sample to be tested, and transmitting the desorbed gas to the sensor reaction chamber (3); An input air circuit (4) is provided with a first electromagnetic valve (41), a first air pump (42) and a sniffing probe (43); one end of the first air pump (42) is connected to the sniffing probe (43), and the other end is connected to the MOFs adsorption tower (2) through the first electromagnetic valve (41); The detection gas circuit (5) is provided with a second electromagnetic valve (51) and a second air pump (52); one end of the second electromagnetic valve (51) is connected to the MOFs adsorption tower (2) and the first electromagnetic valve (41) respectively, and the other end is connected to the sensor reaction chamber (3) via the second air pump (52); The output air path (6) is provided with a third electromagnetic valve (61), one end of which is respectively connected to the second air pump (52) and the sensor reaction chamber (3) through the third electromagnetic valve (61), and the other end of which is exhausted.

2. The sniffer for detecting low-concentration natural volatile gas of drugs according to claim 1, characterized in that: The MOFs adsorption tower (2) comprises a plurality of heating plates (21), a plurality of condensing plates (22), a first shell (23) and a MOFs adsorption tower body (24); the MOFs adsorption tower body (24) is sealed in the first shell (23), and the heating plates (21) and the condensing plates (22) are spaced apart along the circumference of the first shell (23).

3. The sniffer for detecting low-concentration natural volatile gas of drugs according to claim 2, characterized in that: The thickness of the MOFs adsorption tower body (24) coated with the MOFs material is 20-30 μm.

4. The sniffer for detecting low-concentration natural volatile gas of drugs according to claim 2 or 3, characterized in that: The MOFs adsorption tower (2) further comprises a heat insulation sheet (25), which is coated on the outside of the heating sheet (21) and the condensing sheet (22).

5. The sniffer for detecting low-concentration natural volatile gas of drugs according to any one of claims 1 to 3, characterized in that: The input air circuit (4) further comprises a filter device (44) and a drying tube (45), and the filter device (44) and the drying tube (45) are sequentially arranged from the sniffer probe (43) to the first air pump (42).

6. The sniffer for detecting low-concentration natural volatile gas of drugs according to any one of claims 1 to 3, characterized in that: The sensor reaction chamber (3) comprises a sensor array (31) and a second housing (32). The sensor array (31) is arranged in the second housing (32). The sensor array (31) comprises semiconductor sensors (311) and electrochemical sensors (312) arranged at intervals.

7. The sniffer for detecting low-concentration natural volatile gas of drugs according to any one of claims 1 to 3, characterized in that: It also includes a battery (8), which is arranged in the working chamber (11).

8. The sniffer for detecting low-concentration natural volatile gas of drugs according to any one of claims 1 to 3, characterized in that: The housing (1) is also provided with a handle (14).

9. A method for using a sniffer for detecting low-concentration natural volatile gas of drugs according to any one of claims 1 to 8, characterized in that: The steps include: S1. Place the portable sniffer close to the object to be tested; S2. Gas Sample Collection: The MOFs adsorption tower cycles through adsorption, pre-concentration, and desorption of the volatile gases of the test sample, and discharges the desorbed gases into the sensor reaction chamber. S3. Analyze and compare gas samples: The sensor reaction chamber analyzes the data, and the control system compares the data similarity in the database, makes a judgment on the product to be tested, and the test is completed.

10. The method of use according to claim 9, characterized in that: Step S2 also includes the following steps: S21. Filtering and drying the adsorbed gas; S22. Using airflow to clean the MOFs adsorption tower, sensor reaction chamber, and gas lines; S23. The MOFs adsorption tower sniffs the natural volatile gases of the test product for adsorption and pre-concentration; S24. The MOFs adsorption tower is subjected to gradient temperature heating and desorption. Different MOFs materials have different desorption effects on different odor molecules at different temperatures, achieving selective desorption and discharging them into the sensor reaction chamber in sections.

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